1. Field of the Invention
The present invention relates to information processing apparatuses and methods and computer programs therefor. More particularly, the present invention relates to an information processing apparatus that has a plurality of recording media, such as a digital versatile disk (DVD) and a flash memory, and that selects data recorded on each medium and outputs the data to a personal computer (PC) or a printer serving as an external device, and to an information processing method and a computer program therefor.
2. Description of the Related Art
Universal serial bus (USB) has in recent years been widely used in data communication between an information processing apparatus, such as a PC, and its peripheral device. Data communication using USB is performed between a host, such as a PC, and a slave, such as a printer, a mouse, or a display. The slave holds a table referred to as a descriptor describing its attribute. The host, such as a PC, connected via USB to the slave obtains the descriptor from the USB-connected device (slave) to identify a driver compatible with the slave. The host loads the identified driver and performs slave-compatible data communication.
An example of a slave device includes an imager, such as a video camera or a still camera. An imager that has a USB connection terminal and that can be connected via a USB cable outputs imaging data recorded on, for example, a recording medium in the imager and outputs the imaging data via the USB cable to the PC, which in turn can play or edit the imaging data.
The communication standard “PictBridge” allows printing without using a PC by directly connecting a digital camera to a printer via a USB cable and directly outputting imaging data recorded on a recording medium in the imager (digital camera) to the printer.
The USB connection between the imager and the PC involves a communication specification (PC mode) such as the USB mass storage class or picture transfer protocol (PTP). In contrast, the USB connection between the imager and the printer involves the communication specification “PictBridge” standardizing the interface between PTP defining the transport layer and the application layer above the transport layer. Accordingly, different communication specifications are applied.
Even when data is output similarly using a USB cable, the case of outputting data in the “PC mode” and the case of outputting data using PictBridge involve different communication specifications. For example, in the case of a digital camera, when a USB cable is connected to the digital camera, a selection screen is presented on, for example, a monitor of the digital camera to allow a user to select a function.
Known general digital cameras employ a single recording medium. A graphical user interface (GUI) serving as a function selection screen is displayed on a monitor to allow a user to select the “PC mode” in which data recorded on the single recording medium is output to a PC or “PictBridge” in which the data is output to a printer.
Recently, however, there are imagers with a plurality of different recording media, such as a DVD and a flash memory. These imagers can select the appropriate recording medium from among the different recording media to record data. As the number of recording media increases, there is a necessity not only to select the USB function but also to simultaneously select the recording medium.
It is necessary for an information processing apparatus, such as a digital camera, with a plurality of recording media to select the function upon establishment of a USB connection and to change, using a device switch by way of example, the recording medium for which the USB function is performed. Also, in the case where pieces of data are recorded on a plurality of different recording media in a distributed manner, when the pieces of data recorded on these plural different recording media are to be successively viewed and edited on a PC, or when these pieces of data are to be printed, it is necessary to perform complicated and inefficient operations involving selecting one recording medium and the USB function therefor, outputting data to the selected recording medium, selecting thereafter the next recording medium using a hard switch, and selecting the USB function again on the function selection screen displayed on the monitor.
The USB cable is disconnected from the information processing apparatus, such as the imager, with the USB function upon the ending of the USB function. When the USB cable is disconnected, the information processing apparatus such as the imager detects the disconnection of the USB cable, ends the USB function mode, and returns to the normal mode.
Thereafter, upon the reconnection of the USB cable, as has been described above, in the PC mode, it is necessary for the host device (PC) to obtain the descriptor of the slave device and to refer to the descriptor to determine the specification with which the host device communicates with the slave side. Therefore, it takes a time to establish a connection in the PC mode again when the USB cable is disconnected and then reconnected.